In recent years, there has been a vast upsurge in the use of highly sophisticated wheel balancers for balancing wheels prior to their mounting on a vehicle. Such wheel balancers typically employ highly sensitive electronic circuitry and sensors for determining the location and degree of imbalance of a wheel mounted on a shaft forming part of the wheel balancer and which is driven.
In the typical wheel balancer, there is a locating device, frequently in the form of a spring biased cone, surrounding the shaft at the driven end thereof so as to precisely center the wheel about the rotational axis of the shaft. The shaft typically is threaded and a nut is threaded onto the shaft to engage the wheel and firmly hold the same against the locating device prior to testing. Thus, in order to mount or demount a wheel from the shaft, it is necessary to thread the nut onto the shaft or thread the nut off of the shaft, as the case may be.
Because of the large variety of vehicle wheels which are balanced on such wheel balancers, provision must be made in the wheel balancer to accomodate the vast majority of such differing wheel types. This has frequently required that the shaft, or an extension thereof, be relatively long. As a consequence, considerable time may be spent rotating the nut structure on the shaft to the point that it properly engages the wheel in a mounting operation or in rotating the nut to remove the same from the shaft to allow the wheel to be demounted from the balancer. This time spent is costly in terms of labor expense and, in volume operations, considerably decreases the efficiency of the operation by diminishing the number of wheels that may be balanced on a wheel balancer in a given period of time.